title: Infrared absorption of CH3OSO detected with time-resolved Fourier-transform spectroscopy.
abstract: A step-scan Fourier-transform spectrometer coupled with a multipass absorption cell was employed to detect temporally resolved infrared absorption spectra of CH(3)OSO produced upon irradiation of a flowing gaseous mixture of CH(3)OS(O)Cl in N(2) or CO(2) at 248 nm. Two intense transient features with origins near 1152 and 994 cm(-1) are assigned to syn-CH(3)OSO; the former is attributed to overlapping bands at 1154 ± 3 and 1151 ± 3 cm(-1), assigned to the S=O stretching mixed with CH(3) rocking (ν(8)) and the S=O stretching mixed with CH(3) wagging (ν(9)) modes, respectively, and the latter to the C-O stretching (ν(10)) mode at 994 ± 6 cm(-1). Two weak bands at 2991 ± 6 and 2956 ± 3 cm(-1) are assigned as the CH(3) antisymmetric stretching (ν(2)) and symmetric stretching (ν(3)) modes, respectively. Observed vibrational transition wavenumbers agree satisfactorily with those predicted with quantum-chemical calculations at level B3P86∕aug-cc-pVTZ. Based on rotational parameters predicted at that level, the simulated rotational contours of these bands agree satisfactorily with experimental results. The simulation indicates that the S=O stretching mode of anti-CH(3)OSO near 1164 cm(-1) likely makes a small contribution to the observed band near 1152 cm(-1). A simple kinetic model of self-reaction is employed to account for the decay of CH(3)OSO and yields a second-order rate coefficient k=(4 ± 2)×10(-10) cm(3)molecule(-1)s(-1).
authors.affiliation: Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Rd., Hsinchu 30010, Taiwan.
authors.forename: Jin-Dah
authors.initials: JD
authors.lastname: Chen
authors.forename: Yuan-Pern
authors.initials: YP
authors.lastname: Lee
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry; D011789:Quantum Theory; D017550:Spectroscopy, Fourier Transform Infrared; D013454:Sulfoxides / Q000737:chemistry*; D013997:Time Factors
chemical_list: D005609:Free Radicals; D013454:Sulfoxides; D002245:Carbon Dioxide; D009584:Nitrogen